The overarching theme of Dr. Lee’s research is gastrointestinal tract cancer screening and prevention, with a focus on evaluating the natural course of disease, identifying risk factors, and designing, implementing, and assessing preventive programs. Helicobacter pylori is the primary cause of stomach cancer; however, evidence regarding the long-term benefits and risks of its eradication remains limited. Dr. Lee’s work spans the full spectrum of H. pylori screening, from explanatory and pragmatic randomized trials to cohort studies and big data science. His research focuses on the intervention design, program implementation, quality assurance, and effectiveness evaluation in population-based H. pylori screening programs.